1. Field of the Invention
The present invention relates to a method for generating rules for an expert system which is for use in controlling operation of a plant in order to, for example, achieve optimum production in a plant.
2. Description of the Prior Art
Recently, in the technical field of plant engineering, practical expert systems for use in a plant control system have been developed as application of the fruit of artificial intelligence research. Especially, for expert systems of a type of using a set of rules as knowledge representation (namely, what is called rule-based systems), it is very important how optimum rules for increasing productivity and safety in production lines of a plant is generated on the basis of experts' experience or knowledge.
First, an example of the prior art method or process of generating the optimum rules will be described herein-below with reference to FIG. 1 of the accompanying drawings. This conventional process starts with Step 131 whereupon an interview with a well-experienced or expert operator by a knowledge engineer (hereunder abbreviated as a KE). Next, the process proceeds to Step 132 whereupon (candidate) rules are generated by the KE on the basis of knowledge or know-how acquired at the interview made in Step 131. The process then enters Step 133 whereupon the thus generated rules are checked by the expert operator. If one of the rules is not acceptable for the expert operator, the process returns to Step 132 whereupon an alternative rule is generated by the KE. On the other hand, if acceptable, the process advances to Step 134 whereupon the rules are further checked by being tested on a production line of the plant. If the result of the test is unsuccessful, the process returns to Step 132 to generate an alternative rule. However, if successful, the whole process is completed.
In the above-described conventional process for eliciting rules, it is necessary for a KE to make interviews with expert operators over a long period of time in order to make up for uncertainness (that is, lack of objectivity) about the experts' experiential knowledge, that is, embody the know-how. Accordingly, the results of generating rules greatly depend upon the personal capability of a KE who interviews the expert operator. Thus, the above-described conventional process for eliciting rules is disadvantageous in that it is difficult to provide rules with objectivity. The present invention is accomplished to eliminate the above-mentioned defects of the prior art.
It is therefore an object of the present invention to provide method for generating rules for an expert system for controlling operation of production lines of a plant in a short period of time through a semi-automatic process for constructing rules without depending on a personal capability of a KE.